The case for optional preferential voting

Optional preferential voting always advantages the party with the highest first preference vote.

Dean Lewins: AAP Image

There's a strong case for moving to optional preferential voting on principle, but self-interest is also at play. The Coalition better be sure of its push for reform, argues Antony Green, because it could come back to haunt it.

On ABC radio's AM program this morning, opposition spokeswoman on electoral matters Bronwyn Bishop argued the case for a Coalition government introducing optional preferential voting (or OPV) for federal election.

A similar report in The Australian carried comment that the Coalition believed the change would disadvantage Labor and the Greens.

Added together these two stories produce the perfect position for any politician, arguing for a policy that backs a matter of principle, but also helpfully aligns with political self-interest.

However, there is already a spoke in the wheels of change, with Nationals leader Warren Truss hosing down the idea. As recently as 2011 the National Party re-affirmed its position of backing the existing system of full preferential voting.

Last week's brief debate on compulsory voting again revealed that Australian's view voting as more than just a right. It is also seen as a form of social duty, a minimal level of civic engagement that all citizens must engage in.

However, full preferential voting sets a far higher bar for voters. Preferences must be expressed for all candidates, whether known or unknown. To have their first preference counted as formal, voters must distinguish between every candidate on the ballot paper, even between candidates equally disliked, as well as between every serial nutjob who has managed to get on the ballot paper.

A far better principle, if compulsory voting remains in place, is to adopt optional preferential voting, where voters only have to express preferences for the candidates they know and wish to vote for.

The main advantage to flow from optional preferential voting would be to halve the scandalously high level of informal voting at federal elections. Surveys of ballot papers consistently show that around half of all informal votes had at least a valid first preference and so could have been admitted to the count had optional preferential voting been in place.

It has to be pointed out that a switch to optional preferential voting would also be quite a departure for Coalition policy, as full preferential voting has been a fundamental principle of the non-Labor parties for close to a century.

The introduction of preferential voting came about as a reaction to the early rise of the Labor Party. Labor's disciplined ability to nominate one candidate per seat was not matched by the more fluid conservative parties of the day. Full preferential voting was one of several methods adopted to prevent vote-splitting under first-past-the-post voting from delivering victory to Labor.

Federally it was introduced ahead of the 1919 election following the emergence of the Country Party. It allowed the Country Party and the then Nationalist Party to compete with each other, and even to nominate multiple candidates, without concern that vote-splitting would deliver victory to Labor.

Until the 1950s, it was competition in triangular contests where full preferential voting mattered. Labor rarely won contests where it trailed the combined first preference vote of competing Coalition candidates.

As experience at NSW and Queensland state elections has shown, triangular contests become more difficult for the Coalition under optional preferential voting. In both states the Coalition parties have lost seats through their supporters opting not to express preferences. There has not been a three-cornered contest in NSW since 1999, and in Queensland, optional preferential voting was one of the issues that drove the merger of the Liberal and National Parties to form the LNP.

A commitment to optional preferential voting would, I presume, also apply to the Senate. It is the Senate where full preferential voting has most distorted the will of the electorate through group ticket voting, electing candidates from the Nuclear Disarmament Party, Family First and Democratic Labor Party despite polling less than 2.5 per cent of the vote.

But for all the principle, self-interest will also be playing a part in any suggestion by the Liberal Party to adopt optional preferential voting. That is because while it has been the Coalition that has benefited from full preferential voting for most of Australia's political history, the position has reversed since 1980 with the Labor Party becoming the net beneficiary.

Following the Labor Party split that created the Democratic Labor Party (DLP) in 1955, it was the Coalition that benefited from minor party preferences. Between 1955 and 1972, the Coalition won 34 contests where its vote trailed Labor on first preferences, compared to just three instance of Labor winning from behind.

Since 1980 it has been Labor benefiting from third-party preferences, first with the increasing flow of Australian Democrat preferences to Labor, and later with the emergence of the Greens. At 11 elections since 1980, Labor has won 61 contests after trailing the Coalition on first preferences. In the same period the Coalition has won just five such contests.

Under full preferential voting Labor has won 12 contests from behind at federal elections in NSW since 1980, seven after trailing by more than 2 per cent. In the same period under optional preferential voting at state elections, Labor has won just two such contests, and both of those when trailing by only a handful of votes.

More recent events at the 2010 federal election may be playing an important role in driving a change in Liberal Party thinking. Had preferential voting been optional at the 2010 Federal election, it is highly unlikely that Labor would be in government today.

At the 2010 Federal election, 64 of the 150 seats were won by a candidate with a majority on first preferences, and a further 75 won by the highest polling candidate at the start of the count after the further distribution of preferences. Optional preferential voting would have had little impact on these 139 contests.

However, in the 11 contests where the candidate leading on first preferences did not win, optional preferential voting could have changed the result.

In eight seats the Liberal Party led on first preferences only to be run down by Labor after preferences were distributed. In Melbourne Labor led but the Greens won, in Denison Labor led but independent Andrew Wilkie won, and in O'Connor the Liberals led but National Andrew Crook won on Labor preferences.

The table below shows the first preference votes, the result after preferences (two-candidate preferred), and the proportion of preferences flowing to the two final candidates in these 11 seats, plus the three-cornered contest in Richmond won by Labor.

2010 Federal Election - Electorates where preferences changed result

% First Preference

% Two-Candidate Preferred

% PreferenceFlows

Electorate

Labor

Liberal

Other

Labor

Liberal

Labor

Liberal

Corangamite (VIC)

39.5

45.0

15.5

50.4

49.6

70.3

29.7

La Trobe (VIC)

38.2

43.9

17.9

50.9

49.1

71.0

29.0

Robertson (NSW)

39.8

43.5

16.7

51.0

49.0

67.2

32.8

Moreton (QLD)

36.0

43.4

20.6

51.1

48.9

73.5

26.5

Banks (NSW)

43.0

45.5

11.5

51.4

48.6

73.7

26.3

Deakin (VIC)

39.9

41.9

18.1

52.4

47.6

68.8

31.2

Reid (NSW)

41.5

43.1

15.4

52.7

47.3

72.6

27.4

Lilley (QLD)

41.1

41.2

17.7

53.2

46.8

68.3

31.7

% First Preference

% Two-Candidate Preferred

% PreferenceFlows

Ind

Labor

Other

Ind.

Labor

Ind.

Labor

Denison (TAS)

21.3

35.8

42.9

51.2

48.8

69.7

30.3

% First Preference

% Two-Candidate Preferred

% PreferenceFlows

Green

Labor

Other

Green

Labor

Green

Labor

Melbourne (VIC)

36.2

38.1

25.7

56.0

44.0

77.2

22.8

% First Preference

% Two-Candidate Preferred

% PreferenceFlows

Labor

National

Other

Labor

National

Labor

National

Richmond (NSW)

39.2

21.2

39.6

57.0

43.0

45.0

55.0

% First Preference

% Two-Candidate Preferred

% PreferenceFlows

National

Liberal

Other

National

Liberal

National

Liberal

O'Connor (WA)

28.9

38.4

32.8

53.6

46.4

75.3

24.7

Had these votes been recorded under first-past-the-post voting, the Coalition would have won 81 seats at the 2010 election and been in government, not 73 seats and its present position on the opposition benches.

But what about under optional preferential voting? The table below attempts to model optional preferential voting. I have assumed the flow of preferences would be the same, but have modelled three different scenarios of exhaustion rates, 30 per cent, 50 per cent and 70 per cent.

The early elections under optional preferential voting in NSW and Queensland saw exhaustion rates of 30 per cent amongst minor party preferences, but this has risen to 50 per cent over time, and 70 per cent in many electorates at the 2011 NSW and 2012 Queensland elections.

At each exhaustion rate I have modelled a new result and show a party status and estimated margin for each electorate.

Party and Margin By Different Preference Exhaustion Rates

Electorate

Full Preferences

30% Exhausted

50% Exhausted

70% Exhausted

Corangamite (VIC)

ALP 0.4%

LIB 0.6%

LIB 1.3%

LIB 2.0%

La Trobe (VIC)

ALP 0.9%

LIB 0.2%

LIB 1.1%

LIB 2.0%

Robertson (NSW)

ALP 1.0%

ALP 0.1%

LIB 0.5%

LIB 1.2%

Moreton (QLD)

ALP 1.1%

LIB 0.3%

LIB 1.4%

LIB 2.6%

Banks (NSW)

ALP 1.4%

ALP 0.7%

ALP 0.1%

LIB 0.5%

Deakin (VIC)

ALP 2.4%

ALP 1.5%

ALP 0.8%

ALP 0.1%

Reid (NSW)

ALP 2.7%

ALP 1.7%

ALP 1.0%

ALP 0.3%

Lilley (QLD)

ALP 3.2%

ALP 2.3%

ALP 1.7%

ALP 1.0%

Denison (TAS)

IND 1.2%

ALP 1.5%

ALP 3.9%

ALP 6.8%

Melbourne (VIC)

GRN 6.0%

GRN 4.3%

GRN 2.9%

GRN 1.4%

Richmond (NSW)

ALP 7.0%

ALP 8.6%

ALP 10.0%

ALP 11.6%

O'Connor (WA)

NAT 3.6%

NAT 1.2%

LIB 0.7%

LIB 2.9%

As the first eight entries show, the higher the rate of exhausted preferences, the greater the likelihood that the Liberal Party would have retained its lead and won these seats. Experience at state elections also shows that preference flows become more random at higher rates of exhaustion, so Liberal prospects could be even better than shown in the above table.

The entry for Melbourne also shows the Greens would have had a tougher time winning under optional preferential voting, as would National MP Tony Crook in O'Connor. The table clearly shows that Andrew Wilkie's extra-ordinary win from third place would have been very unlikely under optional preferential voting.

However, the result in Richmond shows why the National Party opposes optional preferential. Labor polled 39.2 per cent, the Nationals 21.2 per cent and Liberal 19.1 per cent. Every Liberal vote that exhausts before reaching the Nationals candidate just makes it easier for Labor to win. Labor's margin blows out as the exhausted rate increases, though it would be unlikely for the exhaustion rate between the Coalition parties to reach 70 per cent.

The lesson here is that optional preferential voting always advantages the party with the highest first preference vote. In the current political climate that is the Coalition, barring triangular contests. Had the 2010 Federal election been conducted under optional preferential voting, the Coalition would probably have won.

However, advantage has changed over time. It is only a decade since the rise of One Nation hammered the Coalition in NSW and Queensland because of optional preferential voting.

While in the current political climate the Greens are eating into Labor's support and Green preference flows would be weakened by optional preferential voting, the emergence of Katter's Australian Party and the potential it has to damage flows of preferences may give the Coalition some concerns.

Overall optional preferential voting has a principled advantage over full preferential voting in cutting the informal rate, and in not forcing voters to express preferences they do not have. Optional preferential voting would also allow the mess of the Senate's group ticket voting system to be abolished.

But the Coalition better be sure it supports optional preferential voting on principle rather than out of self-interest.

The NSW Labor Party argued principle in introducing optional preferential voting in 1980, but at times since has lived to regret the decision.